Graphoepitaxy directed self-assembly (DSA) employs a topographical guiding pattern to direct the self-assembly of block copolymers (BCPs). One commonly-used BCP in DSA includes polystyrene (PS) and poly(methyl methacrylate) (PMMA) as the monomeric species, commonly referred to as PS-PMMA. BCPs employing other polymer species are possible, of course, including, for example, polystyrene-polyvinylpyrrolidone (PS-PVP), polystyrene-polydimethylsiloxane (PS-PDMS), polystyrene-polytrimethylsilylstyrene (PS-PTMSS), and polystyrene-polyhydroxystyrene (PS-PHOST).
BCPs may arrange into any number of patterns during self-assembly. Controlling or directing this arrangement enables the formation of patterns useful in semiconductor manufacturing. DSA can therefore be employed in place of multiple steps of patterning and etching during the manufacture of a semiconductor device.